非离子型凝胶球在水中的溶胀行为

以过硫酸铵和N,N,N',N',-四甲基乙二胺氧化-还原体系引发丙烯酰胺聚合,制备球状非离子型水凝胶.利用带刻度的显微镜记录了凝胶球在水中的溶胀扩散过程,采用Tanaka-Fillmore凝胶溶胀动力学模型进行数学处理,得到凝胶网络扩散系数.在此基础上,进一步考察了交联剂、引发剂、单体浓度对凝胶网络扩散系数的影响,结果表明:随着交联剂用量的提高,扩散系数先变小后增大;增加引发剂﹑单体浓度,扩散系数均增大.对凝胶网络扩散系数-温度理论模型进行修正,更加符合实验结果,可用于凝胶网络扩散系数的预测.     

天然植物秸杆制备的两性纤维素PCGD水溶液性质的研究

用浊度法研究了一系列不同结构特征的小麦秸秆羧甲基纤维素接枝甲基丙烯酸氧乙基三甲基氯化铵两性共聚物(PCGD)的溶解性及组成与等电点的关系;研究发现PCGD具有明显的等电点,外加盐能够促进PCGD的溶解,PCGD溶液的粘度随着无机盐浓度的变化出现最大值,完全不同于单一电荷的聚电解质,显示出两性聚合物独有的特征。用粘度法研究了PCGD水溶液的流体力学性质,考察了聚合物浓度、温度、外加无机盐等对溶液流体力学性质的影响。     

交联大豆蛋白凝胶的溶胀性能的研究

制备了大豆蛋白凝胶与戊二醛交联大豆蛋白凝胶,研究了凝胶的溶胀性及其影响因素,以质构仪、扫描电镜对凝胶的质构和断面微观结构进行了表征,结果表明:大豆蛋白浓度为13%,其凝胶溶胀率为15.00g/g;当大豆蛋白浓度为12%,25%戊二醛用量为50μL,交联大豆蛋白凝胶溶胀率为25.1g/g,;氯化钠浓度和水的温度对交联大豆蛋白凝胶的溶胀率有影响,氯化钠浓度从0升至0.1M,交联凝胶溶胀率从25.1减小为5.34g/g;水的温度从20升至60℃,凝胶的溶胀率从21.81增至49.12g/g;质构分析和扫描电镜结果显示,戊二醛交联凝胶比大豆蛋白凝胶具有更高的硬度、弹性、内聚性、破裂强度和更有序的微观结构。     

电解质影响凝胶溶胀行为的研究进展--水的状态和凝胶的溶胀收缩

综述了水凝胶研究的一些新进展。简要介绍了水凝胶中水的存在状态和水合氢键模型,分析了电解质影响水凝胶中水的分子状态和凝胶溶胀收缩的现象,并利用水合氢键模型加以解释,指出有待解决的相关问题。     

Complex Formation of Divalent Cations with Carboxylic Acid Resins as a Factor Determining Different Stationary States of Their Swelling

Three samples of carboxylic acid gel-type cross-linked polyelectrolytes were examined by registering the extent and kinetics of their volume change depending on the temperature, concentration, and nature of external electrolyte solutions, as well as the initial state (ionic form, water content) of the bead. It is found that in some systems the swelling of the bead (as a result of lowering the temperature) proceeds much more slowly than the preceding shrinking (as a result of the increase of temperature). Moreover, the initial volume of the bead is not restored, and a new stationary state of swelling is established. By means of optical dilatometry, it is found that in the systems in which the differences in the stationary states of swelling are found, the beads display plasto-elastic properties, whereas in the absence of such differences the beads show elastic properties. It is found that different stationary states of swelling are also established when the beads of copolymer of methacrylic acid cross-linked with divinylbenzene in Na⁺ form in the dry state and in the NaCl solution-swollen state are placed into a solution of a divalent cation salt. The difference in the stationary states of swelling reaches 12% in 4 N NiCl₂ solution. The substantial differences in the swelling behavior and viscoelastic properties of the resins in their Na⁺, Mg²⁺, Ca²⁺, and Ni²⁺ forms are interpreted in terms of formation of different kinds of complexes of functional groups of the polymer with Ca²⁺ and Ni²⁺ ions.     

复合聚电解质凝胶的制备与性能研究Ⅱ.聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为

采用电导和称重两种方法研究了聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为及温度和pH的影响。与单一聚丙烯酰胺凝胶在相同条件下的溶胀行为比较表明:在一定温度范围内,温度高有利于聚丙烯酰胺/木质素磺酸钙凝胶的溶胀,尤其是高于35℃后更加明显。同时磺化木质素具有在酸性条件下助溶胀和在碱性条件下抑制溶胀的作用,其中pH 11是聚丙烯酰胺/木质素磺酸钙凝胶在酸碱溶液中溶胀的一个临界值。     

复合聚电解质凝胶的制备与性能研究 Ⅱ.聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为

采用电导和称重两种方法研究了聚丙烯酰胺/木质素磺酸钙凝胶的溶胀行为及温度和pH的影响。与单一聚丙烯酰胺凝胶在相同条件下的溶胀行为比较表明:在一定温度范围内,温度高有利于聚丙烯酰胺/木质素磺酸钙凝胶的溶胀,尤其是高于35℃后更加明显。同时磺化木质素具有在酸性条件下助溶胀和在碱性条件下抑制溶胀的作用,其中pH 11是聚丙烯酰胺/木质素磺酸钙凝胶在酸碱溶液中溶胀的一个临界值。     

脱硫微生物对煤溶胀和腐殖酸的影响研究

微生物脱硫与煤的表面更新密切相关,实验考察了微生物脱硫后对煤部分性质的影响,包括脱硫后煤的溶胀情况和腐殖酸含量的变化情况,并记录了微生物脱硫过程中微生物培养液的pH值的动态变化。结果表明,经过脱硫后,微生物对于煤的溶胀有促进作用,在实验最适宜的环境中,溶胀率提高效果较明显,可达到60.6%;对于腐殖酸的提高作用最大可提高27.3%。     

Influence of Diluent on Swelling Behavior,Compressive Properties,and Network Parameters of EPDM/4-tert-Butylstyrene Oil Gels

A series of oil gels based on 4-tert-butylstyrene (tBS) and ethylene-10 propylene-diene (EPDM) cross-linked with determined amount of divinylbenzene (DVB) was synthesized by suspension polymerization. Toluene (Tol), cyclohexane (Cyclohex), and their mixtures with different compositions were used as pore-forming diluents. The influence of diluent type, dosage, and composition on swelling 15 behaviors, compressive properties, effective cross-link density (ne), average molecular weight between cross-links (Mc), and polymer-solvent interaction parameter (v1) of oil gels was studied in this work.     

A Study on the Effect of Butyl Methacrylate Content on Swelling and Controlled-Release Behavior of Poly (Acrylamide-co-Butyl-Methacrylate-co-Acrylic Acid) Environment-Responsive Hydrogels

Poly (acrylamide-co-butyl methacrylate-co-acrylic acid) [poly (AAm-co-BMA-co-AAc)]-based environment-sensitive hydrogels were prepared by varying the butyl methacrylate (BMA) content, in the range of 20 to 66% (wt. of the total monomer) in the hydrogel. The effect of BMA content on the swelling behavior of the hydrogels was studied by keeping the other two monomers' content constant at different pH and temperatures. The synthesized hydrogels were characterized by various techniques, and release kinetics was analyzed. The application and effect of the BMA content of these hydrogels in controlled drug release of acetaminophen and model drugs were investigated.     

Influence of Post-Treatment Temperature on the Stability and Swelling Behavior of Casein Microparticles

This study investigates the influence of exposure time and post-treatment temperature on the stability and swelling of casein microparticles prepared by depletion flocculation and film drying. Stability experiments with sodium dodecyl sulfate at 20 °C show that particles become more stable with higher post-treatment temperature and longer exposure times. The two-step decrease in decay rates in each case indicates a stable intermediate state structurally different from untreated and more strongly treated microparticles. The swelling curves of microparticles also show differences in three temperature ranges at 120 min exposure times each, which is analyzed with dynamic swelling models. At temperatures T ≤ 50 °C, the casein microparticles swell and decompose in a typical two-step process. For post-treatments in the temperature range between T = 60 and 70 °C, the swelling curves change their shape toward limited swelling to an equilibrium swelling value. The swelling curves of microparticles treated with temperatures at 80 and 90 °C show a typical overshooting, which can be analyzed with an adapted parallel swelling model and attributed to an elastic network of newly formed bonds.     

Temperature and pH‐Sensitive Swelling Behavior of Binary DMAEMA/4VP Grafts on Poly(propylene) Films

Poly(N,N‐dimethylaminoethyl methacrylate) (PDMAEMA) is a polymer or hydrogel that is both thermosensitive and pH sensitive, with a low critical solution temperature (LCST) around 38 °C and a pH critical point of 2.5. Poly(4‐vinylpyridine) (P4VP) shows pH sensitivity with a critical point of 5.1. Grafting of stimuli‐sensitive polymers onto mechanically durable poly(propylene) (PP) substrates was used in this study. We have focused on the influence of temperature and pH on the response of binary graft films produced by gamma irradiation in one and two steps. An LCST‐type hydration transition in the grafts was observed by measuring swelling of the films and water contact angle at different temperatures and pH. An upper critical solution temperature (UCST)‐type behavior was also observed by swelling PP‐g‐DMAEMA and DMAEMA/4VP binary grafting onto PP films at pH 2.2.

     

溶胀对新疆淖毛湖煤样结构组成及热解性能的影响

分别采用洗油(WO)、2-甲基萘(MN)和喹啉(QL)三种溶剂对淖毛湖煤样进行溶胀处理,研究溶胀作用对煤样物理和化学结构的影响. 结果表明,与原煤相比,溶胀煤样的挥发分含量和C元素含量不同程度降低,其中C含量降幅明显,约为8.63%,而H和O含量增加. 用WO, MN和QL溶胀的煤样的亚甲基碳含量分别降低6.37%, 5.74%和7.55%,而羧基碳和羰基碳含量分别增至10.60%, 11.40%和11.10%. 溶胀煤样的比表面积比原煤降低30%以上,平均孔径不同程度增加. 溶胀后煤样结构重排,表面能下降. 溶胀煤样的热解焦油产率和气产率均增加,H2和CO产率增幅明显. 溶胀抑制了交联反应,导致CO2产率降低.     

醇酸树脂、氯化聚丙烯与二甲苯三元体系相图的研究

考察不同二甲苯含量时,醇酸树脂、氯化聚丙烯与二甲苯混合液的分层情况,测定其分层一中各成分的组成,作出三元体系相图,从而更全面地了解醇酸树脂、氯化聚丙烯和二甲苯三者的相容性。     

Swelling and elasticity of hydrogels based on poly(ethylene oxide) macroinimer

A novel method for the preparation of hydrogels based on poly(ethylene oxide) (PEO) is presented. A PEO macroinimer possessing both polymerizable and radical generation sites was used to obtain hydrogels having dangling PEO chains. It was shown that PEO macroinimer acts during photopolymerization, both as a monomer and a crosslinker and thus, leads to the formation of hydrogels of various swelling capacities and moduli of elasticity. Copyright © 2004 Society of Chemical Industry     

Polymorphism and Mixing Phase Behavior in Ternary Mixture Systems of SOS–SSO–OSO: Formation of Molecular Compound Crystals

This paper reports the phase behavior of ternary mixtures of saturated and cis‐monounsaturated mixed‐acid triacylglycerols (TAG) of SOS (1,3‐distearoyl‐2‐oleoyl‐glycerol), SSO (1,2‐distearoyl‐3‐oleoyl‐rac‐glycerol), and OSO (1,3‐dioleoyl‐2‐stearoyl‐glycerol) examined with X‐ray diffractometry and a differential scanning calorimeter. The ternary mixtures were crystallized by cooling from melt (60 °C) to 5 °C, and the crystals were then stabilized by storing the mixture samples at 28 °C for 10 days. The following results were obtained. (1) Molecular compound (MC) crystals of stable β polymorph having a double‐chain‐length structure (β‐2) were formed in mixtures of SOS/SSO/OSO in which the concentration of SOS was 50% with varying concentrations of SSO/OSO. This is in contrast to the fact that the stable polymorphic forms of the component TAG are β‐3 for SOS and OSO and β′‐3 for SSO. (2) When the concentration of SOS deviated from 50%, immiscible mixtures of β‐2 MC made of SOS/SSO/OSO and the component TAG (β‐3 of SOS and OSO and β′‐3 of SSO) were formed. Therefore, ternary mixtures of SOS/(SSO + OSO) = 50/50 with different concentrations of SSO and OSO are miscible mixtures of β‐2 of SOS/SSO and SOS/OSO.     

Effect of Branched Alcohols on Phase Behavior and Physicochemical Properties of Winsor IV Microemulsions

The microemulsion phase behavior and physicochemical properties of surfactant–water–alcohol–oil systems are the pioneer laboratory study as a function of alcohol, water content and temperature to develop an experimental investigation for a better understanding of the microstructure of a single phase microemulsion and its stability under reservoir condition during hydraulic fracturing to recover the residual trapped oil. Viscosified surfactants are used as an efficient proppant conducting medium in hydraulic fracturing applications. The physicochemical properties of microemulsions are very helpful for characterization of microemulsions to justify their abilities and screening of surfactants. In the study, two branched alcohols, 2-methyl butan-2-ol, 3-methyl butan-1-ol selected as the cosurfactant in the proposed microemulsion system and their effect in tailoring the viscosity of microemulsions were studied. Microemulsion regions elucidated from Winsor’s pseudophase model of an oleate surfactant show a signatory distribution pattern of components between different domains with non-polar and asymmetric geometry of cosurfactant directs macromolecular alignments; their alignment contributes to a viscous microemulsions (gel) regime. The effect of surfactant and alkali, and the experimental temperature on the rheological properties of the lamellar mesophase were investigated. Phase transit regions and exact microemulsion and viscous microemulsion magnitudes were elucidated with the help of conductivity and viscosity studies of the ternary system as a function of the aqueous fraction and were in good agreement with Winsor’s pseudophase model. Dynamic and steady shear rheological studies showed that the gel is viscoelastic in nature, sustain viscosity and elastic modulus values appropriate for proppant suspension under high shear conditions. The proppant suspension and thermal behavior of ideal gel composition was found to be suitable for Coal Bed Methane and soft rock, clay reservoir stimulation.     

溴代-1-十六烷基-3-甲基咪唑/正丁醇/正辛烷/盐水微乳液体系的相行为和增溶能力研究

用ε-β"鱼形"相图法研究了离子液体表面活性剂溴代-1-十六烷基-3-甲基咪唑(C16mimBr)/正丁醇/正辛烷/盐水微乳液体系的相行为和增溶能力,利用ε-β型HLB平面方程计算了亲水-亲油平衡界面膜的组成及相关物理化学参数。研究发现,水溶液中NaCl的质量分数越大,微乳液的增溶能力越强;固定阴离子浓度,改变阳离子的种类和电荷时,基本不影响C16mimBr形成微乳液的相行为和增溶能力,而固定同价态无机盐浓度,阴离子水化半径的越小,微乳液的增溶能力越强。     

Effects of Temperature and Surfactants on the Equilibrium Swelling Behavior of Poly[acrylamide‐co‐(itaconic acid)] Hydrogels

Summary: The swelling equilibrium of poly(acrylamide) [PAAm] and poly[acrylamide‐co‐(itaconic acid)] [P(AAm/IA)] hydrogels was studied as a function of temperature and IA content in aqueous solutions of surfactants: sodium dodecyl sulfate (SDS, anionic) and hexadecyltrimethylammonium bromide (HTAB, cationic). P(AAm/IA) hydrogels in water exhibited reentrant conformational transitions depending on temperature, whereas PAAm hydrogels were not affected with the change of temperature. The equilibrium‐volume‐swelling ratio of P(AAm/IA) hydrogels increased sharply in SDS solutions, with an increase of the mole percent of IA. However, in HTAB solution, the equilibrium‐volume‐swelling ratio of these hydrogels decreased with an increase of IA content.

The equilibrium volume‐swelling ratios of the hydrogels in water shown as a function of temperature.     

固相法合成孔雀石绿-硼酸复配物及其热变色性能的研究

采用固相法合成了孔雀石绿-硼酸系列可逆热致变色颜料。考察了孔雀石绿和硼酸的配比、无机填料的种类与用量以及环境温度对热变色性能的影响。结果表明：孔雀石绿和硼酸的质量比例在1：(100～400)范围内，颜料在85℃时开始由兰绿色变为黄绿色，加热到110℃时全部变为黄色，冷却时恢复原色，复色时间小于3min；以Al2O3为填料，m(孔雀石绿)：m(硼酸)：m(填料)=1：100：(100～200)，颜料变色敏锐，变色温度降低到75℃，复色时间为小于70s。降低环境温度可以减少复色时间。DSC检测颜料的热变色过程发现70～80℃开始吸热。100～110℃吸热峰达到最大值。